Which chainrings can I use?

fluroforks

Retro Guru
Hi,

I want to gear up my '90 Marin Pine Mountain for road use as I might use it for Lands End John o Groats in the summer.

I was thinking of putting something like an 11t - 24t cassette on the back and 52t 42t 30t on the front. The rear hub is a DX m650 7 speed and the cranks are DX M650 with a 110bcd.

The first problem im having is knowing what road bike chainrings will work with a shimano HG cassette. Im struggling to find larger Shimano 'rings with 110 bcd. I've seen some SR Sakae rings and some Campag on the 'bay but I don't know if they'll work with an HG chain or cassette. Just to confuse the situation I cant find the matching cassette for those SR and Campy rings which will fit a DX Hub.

Can someone clarify what I should be looking for (and please dont say a road bike) in respect of matching rings and cassettes? Also, if i get this set up fitted should I be using a short cage rear mech?
 
if you're sticking with a triple up front then you'll still need a long cage mech, if you switch to a double then a short cage might be more efficient.
 
Don't buy Shimano rings, they are made of metallized cheese and don't last. Try TA or Stronglight: Spa Cycles carry a great selection. Regardless of the speed written on them they will all work absolutely fine (the same goes for any brand). You might find that a complete new chainset is cheaper though.

You won't need a gear bigger than 110 inches: 48/11 is fine even with 1.2" slicks. You won't be aero enough for a bigger gear anyway.

If you are carrying any load, then I'd pick a 24/36/48. 36 is a tad more useful than the typical 34 for road. An 11-28 would be good for the back. What you need is a bottom gear for when you feel shattered. For loaded touring I use 11-28 with 22/36/46, but I have a different chainset.
 
I've not done lands end to j.o.g so don't know what you'll encounter. but around here I can cruise on knobblies and spin out 48/11 on my Fusion.

44/11 only gets me to 35 to 40mph on knobblies.

I have 50/52/54 rings. and a nice Sugino/Tioga stainless 28 inner. can get details later. not sure on a middle compitible one though.
 
If you are regularly spinning out at 48/11 on the flat then I suggest you seek a pro road contract. 120rpm on the cranks gives 50mph. :shock:

I spin out my singlespeed at 130rpm...but the 52" gear means that is around 23mph.
 
I dont think im going to be loaded so should be a steady unladen blast up Britain. Would you still stick with the 48 36 26 and 11/28 with that in mind?

FC: Could you keep those rings to one side for me until I figure out what im going for? I might well end up with a whole new chainset but if Hamsters right I might only need to swap the big ring, I already have the rest.

I've not played around with gearing before, would the front mech have trouble getting from a 28t up to a 50 or 52t?
 
Typically a front mech can handle a 20t difference max. MTB mechs may struggle with anything bigger than 48 as the curve is wrong. Road front mechs are not compatible with indexed MTB shifters.
 
People did run >48 bitd, 48 is always the quoted Max for MTB though (to be fair you never really needed more for offroad so it was never offered.

They easily shift through unramped 24 to 48 setups.

The biggest problem comes with the rear mech, the long cages of old 10 tooth, cannot wrap enough chain with a 11-28 setup.
It's not far off, but you get slack chain on the low low... Edit scratch that not sure of longs, I can only remember the use the medium cage (aka m900)

A modern everyday gentle offroad/onroad, now called trekking, setup is 26/36/48 front and Max 11-36 at the rear (10speed)

If it is generally off road and canal path I would think that sort of setup is fine, road and slicks, you'll probably be fine. If you have them try it for a few days.

hamster":2m2kyrjy said:
Typically a front mech can handle a 20t difference max. MTB mechs may struggle with anything bigger than 48 as the curve is wrong. Road front mechs are not compatible with indexed MTB shifters.
 
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